1 AU is the average distance between the Earth and the Sun and is approximately equal ... This is the speed of light. To calculate the distance in metres for 1 light year, multiply ...

This line illustrates the approximate relative distance between our sun and the center of the galaxy ... etched onto the golden record cover were calculated in the early 1970’s.

An awe-inspiring look at how scientific knowledge builds upon itself gradually – one ingenious measurement at a time ...